To provide a semiconductor device that occupies a small area. The semiconductor device includes a first conductive layer, first to fifth insulating layers, and a second conductive layer that are stacked in this order and further includes a semiconductor layer, a third conductive layer, and a sixth insulating layer. The semiconductor layer is in contact with the top surface of the first conductive layer, the side surfaces of the first to fifth insulating layers, and the second conductive layer. The sixth insulating layer is over the semiconductor layer. The third conductive layer is over the sixth insulating layer and overlaps with the semiconductor layer with the sixth insulating layer between the third conductive layer and the semiconductor layer. The first insulating layer includes a region having a higher hydrogen content than the second insulating layer. The fifth insulating layer includes a region having a higher hydrogen content than the fourth insulating layer. The third insulating layer contains oxygen.